Twin lens camera optical system adjustment module

ABSTRACT

In the double optical system of a twin lens camera, a control device including a single interceptor unit for adjustably varying the size of the exposure apertures of both optical systems. In such a system a control device including a single interceptor unit for inserting filters into both of such optical systems. As useful in such inserter control device, an overcenter spring with one end operated in an arc. A module combining such control devices and such overcenter spring.

United, states Patent 1191 Seiden et a].

1451 :Nov. 27, 1973 [54] TWIN LENS CAMERA OPTICAL SYSTEM ADJUSTMENT MODULE [75] Inventors: Myron A. Seiden, Needham; Charles A. Barr, Waltham, both of Mass.

[73] 'Assignee: Polaroid CorporatiomCambridge,

. Mass.- I y 22 Filed: Jan. 3, 1972 21 Appl. No.: 214,637"

. 521 U. s.c1 ..95/1s ,95/12 .2,95/59 51 Int. Cl. ..G03b 35/10 5s FieldofSearch ..9s 1s,-12.2'

[56] References Cited UNITED STATES PATENTS 2,869,446 1 1959 Franceschini .Q 95/18 I 3,504,607 4/197Q Bok 95/18 1,051,591 1 111913 Huebner. v

1 1,398,952 11/1921 Tessier 95 12.2o

3,381,598 5/1968 Starp .Q 95/59 Primary Examiner-John M. Hor'an Attorney-Brown & Mikulka and Robert L. Berger 57 ABSTRACT I ln the double optical system of a twin lens camera, a 1 control device includinga single, interceptor unit for adjustably varying the sizeof the exposure apertures of both optical systems. in such a system a control device including a single interceptor unit for inserting filters into both of such optical systems. As useful in such inserter control device, an overcenter spring with one end operated in an arc. A module combining such control devices and such overcenter spring.

12 Cla'iins, 9 Drawing Figures PATENTEU NOV 2 7 I975 3.77451 SHEET w 4 FIG. 9

.TWIN LENS CAMERA OPTICAL SYSTEM ADJUSTMENT-MODULE This invention relates to the opticalsys'tems of twin lens cameras and has particular reference to devices for altering the operational characteristics of such systems by adjustment of elements thereof. As one example, it

relates to forming and adjusting iris apertures. As another example, it relates to insertion and removalof light filters and from such systems. Asa further example, it relates to a unique overcenter spring structure for positive action in such alteration.

PRIOR ART Various forms of structures for varyingiris and filter elements of camera systems are found inU.S. Patent Office classification; v

Class 95, subclasses 1.1, 18 and 64R Class 350, subclasses 315'and 318 Class 352, subclasses57, 58, 59, 60 and 62 One Pat., No. 3,442,194 illustrates an iris adjustment scissors'form for a single optical system. r

Another PaL, No. 2,869,446 shows iris aperture change by means of a rotating disc with differentsize pairs of hole s, serving a' pair of optical systems. A'p'air of scissor blades are shown as a shutter mechanism.

7 A furtherPat, No. 1,321,705 shows a; disc for color photography, with different filters and iris aperture registerable in a single lens system.

SUMMARY oF THE INVENTION I In photographic situations in which it is useful to op-' erate a pair of twin optical systems, itisdesirable in view of modern day needs, to provide photographic structure. which is simple and sure in operation, and compact and unitizedin structure- These needs are felt particularly in the sense of treating each of a pair of systerns identically and simultaneously. v One example of use of such systemsis in the produc- "vice or system. This device includes a pair of crossed blades, pivoted andpperable in scissor form andmanner to simultaneously form-and adjust each of a'pair of iris apertures, one in each lens system. Special gear segments on a circle periphery of each suchv blade are couto insert duplicate filter elements simultaneously in 7 each of twin optical systems. This device is manually in the accompanying drawings, wherein:

operated, through gearing to provide shuttle movement to insert and remove such filters. In conjunction with this device, an overcenter spring is used to provide snap action and spring bias holding in each of two rotary positions of the filter/disc. This spring is essentially S- shape to enable it to function compactly in a small area, while yet embodying substantial thrust and stroke.

This invention also provides a unique-and useful modular combination of the above elements and features. This module'can include a full complement of photographic lenses for each of twin photographic optical systems. The module thus is a unitary structure not limited to use in any one specific photographic system,

It is, therefore, an object of thisinvention to provide new and useful iris structure in a twin lens photographic structure.

Another object of this invention is to provide new and useful filter structure in a twin lens photographic structure. 7

A further objectofthis invention is to provide a new and useful snap action structure exemplified in use by a twin lens filter changesystem.

' Still another object of this invention is to provide a photographic twin lens modular unit incorporating the features of the above recited objects in a compact and simple structure.

Other objects and advantages of this invention will be in part apparent and in part pointed out hereinafter and FIG. 1 is an inner face showing of an iris and filter module according to this invention, partly 'cut away;

FIG. 2 isa section or the structure of FIG. 1 as if it- .were whole,=takenessentially on line 2-2 of FIG. 1;

FIG. 3 is a section or the'structure of FIGS. 1 and 2,

- takenessentially 'on line 3-3 of FIG. 2;

" i FIGA isa' cut away perspective as a further illustr 4O tionof the structure of FIGS. 1-3;

FIGS. 5, 6, and 7 are illustrations of iris aperture adjustment bladesaccording to this invention in increments adjustment ofthe irisaperture according to this pled to a single gear train which is manually operable 1 to thus adjust the iris apertures of both opticalsystems in the same manner and degree, and at thesame time.

'This invention provides a feature which assures precise duplication of such twiniris apertures and adjustments and also enables the iris structure to be made inexpensively. This isaccomplished by making'the; iris blades identical in form and dimension, each having a circular'main body and hook like arm extensions with edge cut outs each to form half an aperture. In assembly, one blade can be turned over end for end. This manufacturing tolerances need not be tight because. errors are compensated by the reversal of one of a pair of duplicate blades. 1

Another form of such photographic structure in this invention is -a disc device, pivoted for such rotation as FIG. 8 is an invention; ,4 W

outer form perspective'of a twin lens camera embodying this invention; and

FIG. 9 is a showing of the general interior of the cam era of FIG; 8. I I

This invention is embodied in a twin lens twin optical system module for a camera, and such a module in combinationwith a camera. The camera may be one having a sliding back. Thus, this invention maybe in- 'volved in' a system for producing two or more photographs from a single sheet of film.

Themodule of this invention is mounted in a panel opening in the front of a camera. It comprises, in general, a pair of side-by-side optical systems. A pair of r scissor blade forms is provided as an iris forming and I adjusting structure for both such opticalsystems simulo taneously. Further, a filter disc is provided as a means,

:- such optical systems.

to, the filter disc 10. A sector gear 13 ismeshed with the I upper periphery of the filter gear 12, and is mounted on a rotatable filter disc operating shaft 14. The filter disc has peripheral cutout portions, for example, at 15. The abutments thus formed at 16 and 17 are engaged with an external stop 18 to define two rotary positions of the filter disc 10, 90 apart.

t This rotary movement of the filter disc 10 is back and forth in the 90 arc. The movement is initiated by manual rotary actuation of the filter shaft 14. An overcenter spring 19, in both directions of movement of the filter. disc, at first opposes such manual movement.- Past the center of the arc of movement the spring acts in aid of the manual movement to snap the disc in the direction of such movement, and continues a spring bias of the disc against the stop after the disc reaches either of its two positions. 7

The overcenter spring 19 has one end secured to the stop 18 and the other end secured to'the filter gear 12 other spring end travels in an arc radial to the filter gear 12 as the filter disc is rotated. The spring 19 is formed essentially in an S shape to enable its operation within the confines of the module, and to provide both compression and expansion capabilities suitable to the arcuate movement required of it in a rotary acting device. The double loop of the S form is a means of achieving compactness of design and of distributing the compression and expansion functions of the spring.

The filter disc is provided with four openings in a circle, and 90 apa'rt. Two of these openings 20 and 21 are on a first diameter of the filter disc.'These are empty openings, without filters. As shown, these two'openings each overlie one of a pair of mask openings 22 and 23 in the optical systems of the module of the device of this invention. The other two openings 24 and 25 are on a second diameter of the filter disc, perpendicular to the first diameter. The openings 24 and 25 havese- I sary, on each blade, to form a second, opposite periphlected, identical filters therein. Upon rotation of the fil-- ter disc 90 by operation of the filter disc actuator shaft 14, the filters used in openings24 and 25 are moved into place over themask openings 22 and 23.

As part of the camera operating system, in FIG. 1, a

pair of shutters 26 and 27 are operated up and down from below in a suitable manner to wholly intercept the optical systems light paths through the mask apertures 21 and 22. These shutters are simple, solid, interceptor strips with no openings therethrough.

Further in FIG. 1, there is a crossed blade system for scissor movement to form and adjustably vary an iris aperture in each of the optical systems of this structure as represented by mask openings 22 and 23. These blades are indicated at 28 and 29, and are mounted on the shaft 11 as a mid-point pivot for both of the blades, and in the area of their mutual intersection. The iris blades 28 and 29 are operated by means of a gear train comprising segment gears 30 and 31 as driven by a manually operated segment pinion gear 32. This blade structure and operation is shown in further detail .in

, FIGS. 4, 5, 6, and 7.

opening 33 in FIG. 7. Such adjustment can be made in.

any suitable number of steps, for example, from E8 on down in five stops. t

Each of the blades 28 and 29 is provides with peripheral segments of gear teeth as at 34 on blade 28 and, 35

on blade 29.Thus, blade 28 is rotated to close the iris,

counterclockwise by the gear train 32, 31, 30, and 34.

Blade 29 is simultaneously and oppositely rotated by the gear train 32, 31, and 35. The pinion segment 32 is manually rotated, for such adjustment by manual rotation of 'ashaft on 'which the segment 32 is mounted.

" The general configuration of each of the irisblades,"

for example blade 28, is a circular thin body with the gear segment 34 on one side of the periphery of the circle. The gear segment 34 is thus on a radial arc. On one diamterof the circle form, the blade 28 extends radially one of the blades need only be turned over to provide an opposite, matching blade for one not so turned over. This provides highly useful manufacturing simplification and cost reduction. In such case, it is only neceseral gear segment such as 34A or 35A for'blade 29. In

an assembly of such identical blades, only one of such J segments on each of the blades, will be in use.

In FIG. 2, the modular construction of the device of this invention is shown, with a pair of lens'systems'of a lens unit 39 and a lens 40, and a lens unit 41 and a lens 42, with the filter disc 10 and iris blades 28 and 29 lying between the, lens'units 39 and 41 and their inner lenses 40 and 42. A mask 43 is also shown, in which the FIG. 1 openings 22 and 23 are formed- I The external view, FIG. 8, of a cameraembodying this invention, includes a mainhousing 44 in which the module of this invention is mounted as indicated by the twin lens units 39 and 41. An operating button 45 is shown on a handle, and a back member 46 is partially shown. 7

\ FIG. 9 shows some internals of the camera of FIG. 8. A housing 47 essentially encompasses the module of this invention; see also FIG. 2. Support elements 48 are used to support and guide the shutters 26 and 27, (FIG.

1 A septum 49 is used to separate the twin optical systems one of which is represented by lens units 41. A film pack 50 is mounted in a sliding back 46 which may be moved up and down to present different areas of a film sheet inthe film pack, to the optical systems. The module of-this invention may be incorporated in a twin lens, sliding back, identification photograph camera, in a similar camera system or in any camera system utilizing twin, adjacent, optical systems.

The module is adjusted by turning the pinion 32 to set both the iris apertures at a desired F stop or aperture area. This is accomplished simultaneously, and essentially identically in both optical systems .by adjusting the iris blades 28 and 29 about the mounting shaft 11. As a pivot, and by using the gear trains 32, 30, and 32, 31. i

Also, the filter disc 10 is rotated by turning the gear I segment shaft 14 to rotate the gear 12 and consequently the disc 10. The filter discaffords a choice as between a pair of selected essentially identical filter elements as at 24 and 25, and a pair'of open spaces, as at and 2 1.lfzdesired, insteadof theopen spaces being empty, filter elements different from those M24 and 25 may be'used.

' This invention, therefore,.provides anew and useful module for quick,'simple, and sure operation of a twin lens camera system, with unique means for forming and adjusting iris apertures in each of the optical systems of vention and as changes may be made in the embodiment set forth above without departing from the scope of the invention, it is to be understood that allmatter hereinbefore set forth and in the accompanying drawings'is to be interpreted as illustrative only and notin a limiting sense.

We claim: i y I 1. An optical system module for use in a twin lens camera system, comprising: 7 i

a pair of lens systems;

a pivot shaft mounted betweensaidlens systems and parallel thereto; I,

a pair of iris blades,'cros's mounted on said pivot shaft for scissor adjustment to variably form an iris aperture in both of said lens systems; 7 I

a first gear system'coupled to said iris blades foraccomplishing said adjustment;

a filter disc, also mounted on said pivot shaft for rotation thereon between two positions at one of which a filter is inserted into both of said lens systems;

i a second gear system for rotating said filter disc; and an S shaped overcenter spring connected to snap and bias said filter disc into said twopositions thereof.

2. A camera system comprising:

a pair of optical systems each defining an optical means for forming an iris aperture in each of said optical paths, including a blade unit extending transversely of both of said'optical paths; 2

means for' mounting said blade unit for adjustment to vary the size of both of saidapertures by moving dance with said adjustmenn" means for selectively inserting light filter means 81-;

multaneouslyinto both of said optical paths;

said'inserting means including a pivoted disc with a 7 pair of filters therein, one suchfilter on each side of the pivot of said disc, along a diameter of said said inserting means further including an over center spring mounted generally radially on'said disc for snapping and biasing said disc into position with said filters insaid optical paths.

. 3. A camera system according to claim'2 wherein: I

said blade unit is a pair of crossed blades; and

said mounting means isa pivot in the area of intersec- I 4. A camera system according to claim 2, wherein; 5

tion of said crossed blades.

' path; and

means is provided for accomplishing said adjustment,

including a gear toothform of coupling with a peripheral portion of said blade unit.

6. A camera system according toclaim 2, wherein:

said blade unit is a'pair'of crossed blades;

said mounting means is a pivot in the area of intersection of said crossed blades; and

said crossed blades are essentially identical with each other. I

7. A camera system according toclaim' 2, wherein:

' said blade unit is a pair of crossed blades;

said mounting means is a pivot in thearea of intersection of said crossed blades;

said crossed blades are essentially identical witheach other; and

each of said blades having two edge cut out forms as part of said iris apertures, and peripheral gear'forsaid crossed blades are essentially identical with each other;

each of blades having a circular body centered at said pivot,-a gear form on thej'circle periphery and a pair of extensions one at each end of a diameter of said body;

, each of said extensions having edge out out form as part of one of said iris apertures; and said cut out'forms opening laterally from said diameter, on oppositesides of said diameter, and oppositely with respect to each other.

9.- A camera system according to claim 2, wherein:

' said crossed blades are essentially identical with each other;

' each of said blades having a circular body centered at said pivot, a-pair of gear forms on the circleperiphery, one such gear form at each end of a first diameter of said body, and a pair of extensions one at eachend' of a second diameter of said body;

each of said extensions having an edge cut out form as part of' one of said iris apertures; and

said cut out forms opening laterally from said diame-" ter, on opposite sidesof said diameter, and oppositely with respect to each other.

a 10. A camerasystem comprising:

a'pair of optical systems, each defining an optical path; and I 3 l means for selectively inserting light filter means simultaneously into both'of said optical paths;

saidinsertingmeans includinga pivoted disc with a pair of filters therein, one such filter on each side of the pivot of saiddisc, along a diameterof said said inserting means funherincludingan overcenter -springmounted generally radially on said disc for snapping and biasing said disc into position with said filters in said optical paths.

- 11. A camera system comprising:

a pair of optical systems, each defining and optical a radius of said disc and outwardly beyond saiddisc, and the other end secured to said disc at a point spaced from said disc pivot. 12. A camera system comprising: a pair of optical systems, each defining an optical path; and

means forselectively inserting light filter means simultaneously into both of said optical paths;

said inserting means including a pivoted disc with a pair of filters therein, one such filter on each side of the pivot of said disc, along a diameter of said disc;

said inserting means additionally comprising:

an overcenter spring as a part of said inserting means;

said spring being mounted generally radially on said disc for snapping and biasing said disc into position with said filters in said optical paths; and said spring, in unattached and at rest condition having a shape generally in'the form of an S. 

1. An optical system module for use in a twin lens camera system, comprising: a pair of lens systems; a pivot shaft mounted between said lens systems and parallel thereto; a pair of iris blades, cross mounted on said pivot shaft for scissor adjustment to variably form an iris aperture in both of said lens systems; a first gear system coupled to said iris blades for accomplishing said adjustment; a filter disc, also mounted on said pivot shaft for rotation thereon between two positions at one of which a filter is inserted into both of said lens systems; a second gear system for rotating said filter disc; and an S shaped overcenter spring connected to snap and bias said filter disc into said two positions thereof.
 2. A camera system comprising: a pair of optical systems each defining an optical path; means for forming an iris aperture in each of said optical paths, including a blade unit extending transversely of both of said optical paths; means for mounting said blade unit for adjustment to vary the size of both of said apertures by moving said blade to intercept said optical paths in accordance with said adjustment; means for selectively inserting light filter means simultaneously into both of said optical paths; said inserting means including a pivoted disc with a pair of filters therein, one such filter on each side of the pivot of said disc, along a diameter of said disc; and said inserting means further including an overcenter spring mounted generally radially on said disc for snapping and biasing said disc into position with said filters in said optical paths.
 3. A camera system according to claim 2, wherein: said blade unit is a pair of crossed blades; and said mounting means is a pivot in the area of intersection of said crossed blades.
 4. A camera system according to claim 2, wherein: said blade mounting means is a pivot; and means is provided for accomplishing said adjustment by engaging a peripheral portion of said blade unit to move at least a part of said blade unit about said pivot.
 5. A camera system according to claim 2, wherein: said blade unit mounting is a pivot; and means is provided for accomplishing said adjustment, including a gear tooth form of coupling with a peripheral portion of said blade unit.
 6. A camera system according to claim 2, wherein: said blade unit is a pair of crossed blades; said mounting means is a pivot in the area of intersection of said crossed blades; and said crossed blades are essentially identical with each other.
 7. A camera system according to claim 2, wherein: said blade unit is a pair of crossed blades; said mounting means is a pivot in the area of intersection of said crossed blades; said crossed blades are essentially identical with each other; and each of said blades having two edge cut out forms as part of said iris apertures, and peripheral gear formation as part of means for accomplishing said movement of said blade unit.
 8. A camera system according to claim 2, wherein: said blade unit is a pair of crossed blades; said mounting means is a pivot in the area of intersection of said crossed blades; said crossed blades are essentially identical with each other; each of said blades having a circular body centered at said pivot, a gear form on the circle periphery and a pair of extensions one at each end of a diameter of said body; each of said extensions having an edge cut out form as part of one of said iris apertures; and said cut out forms opening laterally from said diameter, on opposite sides of said diameter, and oppositely with respect to each other.
 9. A camera system according to claim 2, wherein: said blade unit is a pair of crossed blades; said mounting means is a pivot in the area of intersection of said crossed blades; said crossed blades are essentially identical with each other; each of said blades having a circular body centered at said pivot, a pair of gear forms on the circle periphery, one such gear form at each end of a first diameter of said body, and a pair of extensions one at each end of a second diameter of said body; each of said extensions having an edgE cut out form as part of one of said iris apertures; and said cut out forms opening laterally from said diameter, on opposite sides of said diameter, and oppositely with respect to each other.
 10. A camera system comprising: a pair of optical systems, each defining an optical path; and means for selectively inserting light filter means simultaneously into both of said optical paths; said inserting means including a pivoted disc with a pair of filters therein, one such filter on each side of the pivot of said disc, along a diameter of said disc; and said inserting means further including an overcenter spring mounted generally radially on said disc for snapping and biasing said disc into position with said filters in said optical paths.
 11. A camera system comprising: a pair of optical systems, each defining and optical path; and means for selectively inserting light filter means simultaneously into both of said optical paths; said inserting means including a pivoted disc with a pair of filters therein, one such filter on each side of the pivot of said disc, along a diameter of said disc; said inserting means additionally comprising an overcenter spring; said spring having one end secured to a fixed stop on a radius of said disc and outwardly beyond said disc, and the other end secured to said disc at a point spaced from said disc pivot.
 12. A camera system comprising: a pair of optical systems, each defining an optical path; and means for selectively inserting light filter means simultaneously into both of said optical paths; said inserting means including a pivoted disc with a pair of filters therein, one such filter on each side of the pivot of said disc, along a diameter of said disc; said inserting means additionally comprising: an overcenter spring as a part of said inserting means; said spring being mounted generally radially on said disc for snapping and biasing said disc into position with said filters in said optical paths; and said spring, in unattached and at rest condition having a shape generally in the form of an S. 